Dropbox is a service that hosts files and is frequently referred to as "cloud storage." Although there are numerous rivals, such as Microsoft OneDrive, Box, Sync, and Google Drive, Dropbox is one of the oldest and most widely used cloud storage services available today.

You can download entire folders from your Dropbox account to your Android device with the Folder Downloader for Dropbox app:

• The ability to instantly create new folders on the local storage, eliminating the need for a separate file manager.
• Allows for storage on both internal and SD cards (defaults to device-defined external storage, navigate up to find other storage options)
• Background downloads are done using an Android Service, so you don't need to keep the app open.